Transparent nanoemulsions comprising lauric oil

ABSTRACT

The invention relates to oil-in-water emulsion in which specific oils (e.g., lauric oils) are used in the oil phase while surprisingly maintaining excellent transparency. In one aspect, said emulsions comprise fatty acid in oil phase. In a separate co-pending application, the invention comprises an energy efficient process for making said fatty acid containing transparent nanoemulsions.

FIELD OF THE INVENTION

The present invention relates to novel oil-in-water nanoemulsions. Theinternal phase comprises lauric oils, such as coconut oil, palm kerneloil and mixtures thereof. Highly saturated oils such as these are usedfor skin moisturization, but are not considered suitable for use in oilcontinuous transparent cleansing compositions because such oils aretypically opaque and semi-solid (due to high degree of saturation) atambient temperature. Surprisingly, when lauric oils are used, excellenttransparency is achieved, particularly in systems comprising anioniccleansing surfactant in the aqueous phase and high levels of glycerol.Further, nanoemulsions, preferably having at least minimal levels ofamphoteric surfactant in the aqueous phase, permits good foaming.

BACKGROUND OF THE INVENTION

Generally, oil continuous transparent cleansing oil compositions, suchas Dove® Nourishing Care shower oil, are desirable because suchcompositions are attractive (consumers desire transparent compositions)while simultaneously providing excellent cleansing and moisturization(e.g., the oils are moisturizing agents).

Such transparent oil compositions are typically delivered in the form ofoil soluble surfactants which are solubilized in liquid vegetable oils,such as sunflower oil, soybean oil etc. These vegetable oils aretypically high in oleic (18:1), and linoleic (18:2) acid. The high levelof unsaturation makes this composition prone to oxidation. Oil solublesurfactants used in these systems typically also provide much poorerlather performance (lather being another desirable attribute) thantypical anionic and amphoteric cleansing surfactants.

Coconut and palm kernel oil contain high levels of medium- andlong-chain saturated fatty acids. Both oils are rich in lauric acid. Forpurposes of our invention, oils that contain high level of lauric acid(12:0), saturated C₁₂ length fatty acid (30% or more of fatty acidcomposition of the oil or oils), are called lauric oils. The high levelof saturation makes lauric oils stable against oxidation; however, suchhighly saturated oils have higher melting point compared with otherliquid vegetable oils. Because they become semi-solid (due to highmelting point) at ambient temperature, they would not be consideredsuitable for use in oil continuous cleansing liquid compositions whichare transparent.

There is thus a need to develop a cleansing composition that is rich inlauric oils (will not oxidize as readily as more unsaturated oils) whichcan retain excellent transparency and which can further providesatisfactory lather.

Transparent nanoemulsions are known in the prior art. U.S. Pat. No.8,834,903 to Simonnet et al. discloses nanoemulsions which are said tobe transparent comprising an oil phase which may contain oils chosenfrom oils of animal or vegetable origin (column 4, lines 25-26), andfurther comprising non-ionic surfactant, sugar fatty esters or sugarfatty ethers, with transparency measured by Nephelometric TurbidityUnit, or NTU, values ranging 60 to 600 NTU. It further discloses theemulsions comprise glycols, such as glycerol to help improve thetransparency of the formulation.

U.S. Pat. No. 7,393,548 to Friedman discloses cosmetic or pharmaceuticalcompositions in the form of oil-in-glycerin emulsion to facilitatestratum-corneum penetration and dermal penetration of bioactivecompound. The oil may be coconut oil although there is no recognition ofadvantage of one type of oil versus another regarding transparency. Thereference makes no mention of transparency. There is also no disclosureof surfactant systems comprising anionic surfactant.

Nanoemulsion compositions comprising triglyceride oils in an internalphase and anionic surfactant(s) in an external aqueous phase are alsonot new. Applicants have filed applications (e.g., EP Application No.16166487) directed to (1) an internal phase comprising triglyceridesoils and/or petrolatum (as well as fatty acid); and (2) an externalphase having specific surfactant (e.g., amino acids based surfactants).There is no disclosure in this application of such compositions beingtransparent or that such transparency is achievable in the presence ofspecific types of oils. There is no disclosure that, if using fattyacids, the melting point of fatty acid or of a mixture of fatty acids isfurther critical to achieving transparency. There is no recognition ofprocessing criticalities and no disclosure of formation of transparentnanoemulsion comprising fatty acid, especially an energy efficientprocess for making particularly high transparency compositions, such asdisclosed by applicant in a co-pending application.

None of the references above describes nanoemulsions comprising highlysaturated lauric oils (i.e., that will not readily oxidize) whichmaintain excellent transparency; and which simultaneously providesatisfactory lather as well as desirable moisturization. Further, noneof the references disclose a method for preparing the transparent lauricoil nanoemulsions in an efficient way.

SUMMARY OF THE INVENTION

Unexpectedly, applicants have now discovered lauric oil nanoemulsionsthat maintain excellent transparency and which comprise highly watersoluble anionic and/or amphoteric cleansing surfactants. Thecompositions are efficiently prepared with at least one pass through ahomogenizer at a pressure of 7,000 psi or less (482.6 bar or less; toconvert from psi to bar, we divide the pressure value by 14.504), andthe resulting composition simultaneously provides desirablemoisturization (from oils and humectants present), satisfactory lather,and highly transparent compositions (measured by Nephelometric TurbidityUnit, or NTU, values less than 100, preferably less than 60) desirableto the consumer.

More specifically, in one aspect, compositions of the invention comprisean oil-in-water nanoemulsion wherein said nanoemulsion comprises:

-   -   1) an internal oil phase comprising 3.5% to 40%, preferably 5 to        40% or 10% to 40% by wt. nanoemulsion composition of a lauric        oil, said lauric oil defined as an oil(s) wherein saturated 012        length fatty acid (12:0) comprises 30% or more, preferably 30%        to 85% of the fatty acid composition of the oil or oils.        Preferably, the oil is an oil selected from the group consisting        of coconut oil, palm kernel oil, various other lauric oils noted        below and mixtures thereof; and    -   2) an external aqueous phase comprising:        -   i. 55 to 90% by wt. nanoemulsion of water and glycerol,            wherein the ratio of said glycerol to said water is 2.5:1            and higher, preferably 2.8:1 to 10:1 or 3:1 to 5:1; and        -   ii. 3 to 12% of a surfactant system comprising water soluble            surfactants selected from the group consisting of anionic            surfactants, amphoteric surfactants and mixtures thereof,            wherein said anionic surfactant comprises 15% or more,            preferably 40% or more (up to 100%, preferably 95%, although            preferably it is 40% to 85%, or 50% to 85%, that is, there            is at least some amphoteric surfactant) of the total            surfactant system;    -    wherein said composition has a Turbidity of less than 100 NTU,        preferably less than 90 NTU, more preferably 80 to 1 NTU or 70        to 2 NTU, most preferably 60 to 5 NTU.

The nanoemulsion of the invention is typically prepared by combining anoil phase comprising lauric oil(s) and an aqueous phase comprisingsurfactant, glycerol and water in a conventional mixer, and passing themixture through a homogenizer for 1 or 2 passes (or more if desired) athomogenization pressure of 7000 psi (pounds per square inch) or less(482.6 bar or less), preferably 1500 psi to 5500 psi (103.4 to 379.2bar). The greater the number of passes, the lower the NTU value (seeExample 7 versus Example 8). Alternatively, the nanoemulsion can beprepared by simultaneously pumping the oil phase and aqueous phase intoa homogenizer, without being mixed in a conventional mixer.

The temperature for preparing the nanoemulsion is from ambienttemperature to 60° C.

Preferably, the volume average diameter, D[4,3], of oil droplets is 100nm or lower, more preferably 20 to 95 or 30 to 85 or 40 to 75.

Unexpectedly, nanoemulsion delivering excellent moisturizing oils,humectant (e.g., glycerol) and good foaming attributes, all whilemaintaining excellent transparency, can be obtained.

In another aspect, the internal oil phase further comprises 0.1 to 7% bywt. nanoemulsion composition of a fatty acid or fatty acid mixture,wherein the melting temperature of the fatty acid or mixture of fattyacids is −10° C. to 30° C., preferably 0° C. to 25° C., or 5° C. to 20°C. Fatty acids or mixture of fatty acids with a melting temperaturehigher than 30° C. tend to cause haziness and gelling in thenanoemulsion, resulting in non-transparent nanoemulsons at ambienttemperature (Comparatives F and G). Of course, if heated, e.g., at above40° C., the composition is both fluid and transparent.

In another aspect of the invention, the subject of a related co-pendingapplication, the efficiency of making a transparent nanoemulsioncomprising fatty acid can be further improved. Specifically, theinvention relates to a less energy intensive process (e.g., using onepass only through a high pressure homogenizer) to obtain nanoemulsioncompositions having free fatty acid(s) in the oil phase and a turbidityof 45 NTU or less, preferably 40 NTU or less or 35 NTU or less or 30 NTUor less. The process comprises first preparing a concentrate emulsioncontaining an oil phase additionally comprising fatty acid or mixture offatty acids having a melting point of 30° C. or lower, wherein said oilphase is typically present at level of greater than 50 to 85% of thenanoemulsion; and an aqueous phase comprising glycerol and water at aratio of 1:2 to 2:1. The concentrate emulsion is prepared in aconventional mixer equipped with a rotor/stator high shear device at arotor speed of 3000 to about 7000 rpm or through a low pressurehomogenizer at pressure of about 200 to 500 psi (13.8 to 34.5 bar); theconcentrate is then diluted to a desired oil range (about 5 to 40%,preferably 10 to 38% by wt. nanoemulsion oil; as discussed later, intheory the 5% lower limit may comprise as high as much as 1.5%non-lauric triglycerides and 3.5% lauric triglyceride oils) and to adesired ratio of glycerol to water (2.5:1 and higher, preferably 2.8:1to 10:1 or 3:1 to 5:1); and passing the diluted emulsion through highpressure homogenizer once. This alternative process is advantageous overthe process typically used in this application because it allows use ofonly a single pass through high pressure homogenizer (much less energyintensive) while providing better transparency (measured by turbidity of45 NTU or less; 40 NTU or less, or 35 NTU or less) than the process inthe current application (see Examples 7, used as a Comparative for thisprocess, compared to Example 12c).

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is schematic of typical process which does not use concentrate,followed by dilution.

FIG. 2 is schematic of process where concentrate is formed, followed bydilution.

DETAILED DESCRIPTION OF THE INVENTION

Except in the operating and comparative examples, or where otherwiseexplicitly indicated, all numbers in this description indicating amountsof material or conditions of reaction, physical properties of materialsand/or use are to be understood as modified by the word “about.” Allamounts are by weight of the final composition, unless otherwisespecified.

It should be noted that in specifying any range of concentration oramount, any particular upper concentration can be associated with anyparticular lower concentration or amount.

For the avoidance of doubt the word “comprising” is intended to mean“including” but not necessarily “consisting of” or “composed of.” Inother words, the listed steps, options, or alternatives need not beexhaustive.

The disclosure of the invention as found herein is to be considered tocover all embodiments as found in the claims as being multiply dependentupon each other irrespective of the fact that claims may be foundwithout multiple dependency or redundancy.

Nanoemulsions of the subject invention are able to deliver excellentmoisturizing lauric oils, highly saturated oils which have high meltingpoint and typically would be expected to result in opaque oil continuouscleansing compositions (because high melting point makes them seem solidand they're opaque). Unexpectedly, using these lauric oils as internalphase, using defined ratio of glycerol to water, mixing under relativelyless energy intensive process (using at least 1 pass through homogenizerat 7000 psi or less), and using highly water soluble anionic and/oramphoteric surfactants in the aqueous phase of the nanoemulsions, it ispossible to obtain compositions which retain excellent transparency andfurther provide good foam. The compositions further providemoisturization from oils (lauric oils) and humectant (e.g., glycerol).

In another aspect, the invention provides nanoemulsions additionallycomprising fatty acid or fatty acid mixtures in the oil phase havingdefined melting temperature of such fatty acid or mixture (−10° C. to30° C.). In a co-pending application, the invention provides even lessenergy intensive method of making nanoemulsion comprising said oil phasewhich additionally comprises fatty acid or mixture of fatty acids whileobtaining excellent transparency values.

The invention is defined with more particularity below.

Oil Phase

Vegetable oils are frequently used in cosmetic compositions asmoisturizers. The main constituent of vegetable oil is triglyceride ortriacylglycerol, an ester derived from a glycerol and three fatty acids.The composition of the fatty acid ester-linked to the glycerol moietyrespectively defines the physical and chemical properties oftriglyceride oils. Frequently used vegetable oils in cosmeticcompositions such as sunflower oil and soybean oil are liquid at ambienttemperatures and prone to oxidation due to the high level of unsaturatedcomponents, e.g. oleic (18:1), and linoleic (18:2) acid, in their fattyacid composition. Hence their iodine value (a measure of the amount ofunsaturation in the oils, expressed in the mass of iodine in grams thatis consumed by 100 grams of oil) is typically in the range of 80 to 140.

Oils in the internal phase of the oil-in-water nanoemulsion (of bothco-pending and the subject invention) are lauric oils, a group of oilsthat are high in lauric acid (12:0), present at levels between 30 and85%, unlike most of vegetable oils. Lauric oils of our invention alsotypically contain 5 to 20% medium chain C₈ and C₁₀ saturated fatty acid.The lauric oils include coconut oil, palm kernel oil, babassu, tukum,murumuru, ouricuri, cohune, some cuphea oils and lauric algal oil.Coconut and palm kernel oil are most commercially developed while theothers are to a lesser degree. Preferred oils in the internal phase ofthe subject invention are coconut oil, palm kernel oil and mixturesthereof. Typically, IV value of lauric oils of the invention is 50 orbelow, for example, 0.5 to 50.

Coconut oil is an edible oil derived from the coconut palm (Cocusnucifera). Palm kernel oil is produced from the kernels of the oil palm.Both contain high levels of medium- and long-chain saturated fattyacids. Both oils are rich in lauric acid, but differ in their levels ofcaprylic (8:0), capric (10:0) and oleic (18:1) acids. Coconut oil ismore saturated than palm kernel oil, hence the iodine value of theformer is lower than the latter at 6-10 and 14-21 respectively. This iswell below typical iodine values of above 50, typically 80 to 140typically found in oils such as sunflower oil and soybean oil as notedabove. Because highly saturated lauric oils of our invention are high insaturated content, they are slow to oxidize compared with othervegetable oils. Slow oxidation is an important component of ourinvention.

The fatty acid composition of typical lauric oils of our invention isnoted in the Table below.

Typical Fatty Acid Composition (% wt.) of Lauric Oils Adapted fromGunstone* Oil source 8:0 10:0 12:0 14:0 16:0 18:0 18:1 18:2 Coconut 8 748 16 9 2 7 2 Palm kernel 3 4 45 18 9 3 15 2 *F. D. Gunstone, in W. Hammand R. J. Hamilton, eds., Edible Oil Processing, Sheffield AcademicPress, Sheffield, U.K., 2000, pp. 1-33.

The melting point of coconut oil and palm kernel oil is 23 to about 26°C. and 23° C. to about 30° C., respectively.

Lauric oils can be hydrogenated (i.e., made even more saturated) tofurther enhance their stability and color. Hydrogenation increases themelting point of coconut and palm kernel oil to about 32° C. and about40° C. respectively.

Although these lauric oils are excellent moisturizing oils, they wouldnot be contemplated for use in oil continuous transparent cleansingcompositions because these oils are typically semi-solid at ambienttemperature, due to their high degree of saturation.

The lauric oils, when used in the subject application, typically rangefrom 5 to 40% (assuming all the oils in the oil phase are lauric oils)by wt. of total nanoemulsion composition. The preferred volume averagediameter of the droplet (measured as D[4,3]) is 100 nm or lower,preferably 20 to 95 or 30 to 85 or 40 to 75. This is also the finalrange of oils of the co-pending invention, but the initial concentrateemulsion comprises oil at greater than 45% to 85% of emulsion.

Surprisingly, applicants have found that, unlike the lauric oils of ourinvention, not all triglyceride based oils, will form transparentcompositions, even when using the compositions and processes of thesubject invention. For example, in one composition example, applicantsshow that sunflower oil (a high oleic oil with an iodine value of 87),used in a composition which is identical except that coconut oil isused, has a turbidity value of 163 NTU versus 32.8 NTU when the moresaturated coconut oil is used (see Comparative A versus Example 1). Itshould be noted that some small amount of non-lauric triglyceride oils,which typically have a higher level of unsaturation (iodine value ofabove 50), for example sunflower oil, grape seed oil, argan oil etc. maybe used as partial replacement for the 5-40% lauric oils in the oilphase of nanoemulsions. However, they should not replace more than 30%of such lauric oils in order to maintain the transparency and, there isminimum 5% oil (i.e., minimum 5% total lauric oil and non-lauric oil).Specifically, if there is 5% total oil as percent of nanoemulsion, intheory the oil phase may comprise 1.5% non-lauric oil (30% of 5%) and3.5% lauric oil. So total lauric oil may be 3.5% to 40% lauric oil.Conversely, the 5 to 40% oil in the oil phase may be 100% lauric oils.

Cuphea oil is another lauric oil which may be used. It is pressed fromthe seeds of several species of the genus Cuphea. C. painteri, forexample, is rich in caprylic acid (73%), while C. carthagenensis oilconsists of 81% lauric acid and C. koehneana oil capric acid (95%).These oils are highly saturated and are suitable for use in thisapplication either individually (e.g. high lauric C. carthagenensis) oras oil blends of high lauric and high caprylic and/or capric cupheaoils. If used in a blend, as noted above, total level of lauric acid inoil blend, for purposes of our invention, is at least 30%.

Lauric oils, suitable for use in this application, may be produced bygenetic engineering techniques. Lauric algal oil from Solazyme® is oneexample.

In addition to defined oils, the oil phase may comprise oil soluble skinbeneficial actives such as, for example, Vitamin A, Vitamin E,sunscreens, fragrances, retinol palmitate, esters of 12 hydroxystearicacid, conjugated linoleic acid; antibacterial agents; mosquitorepellents; essential oils etc. at level of 0.01 to 5%.

Another ingredient which could be found in the oil phase is an oil phasestabilizer. For example, small amounts (0.01 to 2% preferably 0.1 to 1%by wt. nanoemulsion) of antioxidants may be used. A preferredantioxidant is butylated hydroxytoluene (BHT).

Finally, in one aspect of the invention, the invention provides that theoil phase comprises 0.1 to 7% by wt. nanoemulsion composition fatty acidhaving melting point of −10° C. to 30° C., preferably −5° C. to 25° C.or 0° C. to 20° C.; or mixture of fatty acids with melting point of themixture of −10° C. to 30° C., preferably −5° C. to 25 or 0° C. to 20° C.This is a required component in the co-pending application relating toconcentrate-dilution process. It should be noted that fatty acidsdiscussed here are free fatty acids, not to be confused with the fattyacids ester-linked to glycerol moiety in triglyceride oils as discussedpreviously.

The fatty acids or fatty acid mixtures suitable for this applicationwith melting points −10° C. to 30° C. are listed below.

Saturated branched fatty acids typically have a low melting pointcompared with their linear counterpart. Their solubility in organicsolutions is high and so is the solubility of their corresponding saltsin aqueous solutions. A typical example is isostearic acid (methylheptadecanoic acids), which is a liquid isomer of stearic acidconsisting of a mixture of monobranched fatty acids. Commerciallyavailable isostearic acids include, e.g., Emersol® 3875 with up to 80%isostearic and isopalmitic acid, produced by Emery Oleochemicals andPrisorine™ 3505 produced by Croda. The cosmetic-grade isostearic fattyacids are water white in color, the iodine value is about 3.0 or less,and the melting point is about 6° C.

Unsaturated fatty acids with a single double bond such as myristoleicacid has a melting point of about 4° C. and oleic acid has a meltingpoint of 16° C. Unsaturated fatty acids with two or more double bondswith a melting of point of about 0° C. to 30° C., e.g. linoleic acid,are also suitable to this application.

Saturated straight chain fatty acids with a chain length less than 10carbons, e.g. caprylic acid has a melting point of 17° C.

Fatty acid mixtures suitable to this application can be the mixture offatty acids each with a melting point below 30° C. mixed in any ratio.

A fatty acid with melting point above 30° C. and one with melting pointbelow 30° C. can be mixed with a specific ratio such that the meltingpoint of the mixture is below 30° C. e.g., isostearic acid and lauricacid mixed in a ratio of 70/30 (wt. %).

Another way to obtain fatty acid mixtures with melting point lower than30° C. is by mixing fatty acids that can form a binary eutectic mixture,whose melting temperature is lowest. For example, suitable for thisapplication, capric acid-lauric binary system forms a eutectic with themixture ratio of 66:34 (wt. %), which melts at 20° C., lower than 32° C.(capric acid's melting point) and 44° C. (lauric acid's melting point),both of which is out of the scope of this application. Another example,oleic acid can form eutectic mixtures with lauric and myristic acidrespectively, with melting point of eutectic mixtures of about 10° C.

Also suitable for this application are coconut fatty acids or palmkernel fatty acids which are mixtures of C₈ to C₂₂ fatty acid with amelting point of 22-26° C.

Lauric acid alone, for example, has a melting point greater than 40° C.and fails to produce desirable transparent nanoemulsion. However, a50:50 mixture (wt. %) of lauric and isostearic acid has melting pointbelow 25° C. and produces the desired transparent nanoemulsions asdefined by NTU values noted.

Aqueous Phase

The aqueous phase comprises water soluble surfactant system comprisingwater soluble surfactants which are selected from the group consistingof anionic surfactants, amphoteric surfactants and mixtures thereof,wherein the anionic surfactant comprises 15% or more, preferably 40% ormore anionic. Although these may be 100% anionic, preferably there is atleast some amphoteric surfactant present and anionic comprises 15% to95% or 40 to 85% of the surfactant system.

One class of anionic surfactant which may be used are alkyl and alkylether sulfates, having respective formulae ROSO₃M and RO(C₂H₄O)_(x)SO₃M,where R is alkyl or alkenyl of about 8 to 18 carbons. X is an integer of1 to 10, and M is a cation such as ammonium;

alkanolamine, such as triethanolamine; monovalent metal, such as sodiumand potassium.

Other suitable anionic surfactants are the water-soluble salts oforganic, sulfuric acid reaction products confirming to the formula[R¹—SO₃-M] where R¹ is a straight or branched chain, saturated,aliphatic hydrocarbon radical having from about 8 to about 24,preferably from about 10 to about 18, carbon atoms; and M is a cationdescribed hereinbefore.

Still other suitable anionic detersive surfactants are the reactionproducts of fatty acids esterified with isethionic acid and neutralizedwith potassium hydroxide where, for example, the fatty acids are derivedfrom coconut oil or palm kernel oil; potassium salts of fatty acidamides of methyl taurate in which the fatty acids, for example, arederived from coconut oil or palm kernel oil.

Other anionic surfactants suitable for use in the compositions are thesuccinnates, examples of which include disodiumN-octadecylsulfosuccinnate; disodium lauryl sulfosuccinate; diammoniumlauryl sulfosuccinate; tetrasodiumN-(1,2-dicarboxyethyl)-N-octadecylsulfosuccinnate; diamyl ester ofsodium sulfosuccinic acid; dihexyl ester of sodium sulfosuccinic acid;and dioctyl esters of sodium sulfosuccinic acid.

Other suitable anionic surfactants include olefin sulfonates having fromabout 10 to about 24 carbon atoms. In addition to the true alkenesulfonates and a proportion of hydroxyl-alkanesulfonates, the olefinsulfonates can contain minor amounts of other materials, such as alkenedisulfonates depending upon the reaction conditions, proportion ofreactants, the nature of the staring olefins and impurities in theolefin stock and side reactions during the sulfonation process.

Another class of anionic surfactants suitable for use in thecompositions is the beta-alkyloxy alkane sulfonates. These surfactantsconform to the Formula (1):

where R¹ is a straight chain alkyl group having from 6 to about 20carbon atoms, R² is a lower alkyl group having from 1 to 3 carbon atoms,preferably 1 carbon atom, and M is a water-soluble cation as describedhereinbefore.

Preferred anionic surfactants for use in the compositions includeammonium lauryl sulfate, ammonium laureth sulfate, trimethylamine laurylsulfate, trithylamine laureth sulfate, triethanolamine lauryl sulfate,triethanolamine laureth sulfate, monoethanolamine lauryl sulfate,monethanolamine lauryl sulfate, diethanolamine lauryl sulfate,diethanolamine lauryl sulfate, lauric monoglyceride sodium sulfate,sodium lauryl sulfate, sodium laureth sulfate, potassium lauryl sulfate,potassium laureth sulfate, sodium lauryl sarcosinate, sodium lauroylsarcosinate, ammonium cocoyl sulfate, ammonium lauroyl sulfate, sodiumcocoyl sulfate, sodium lauroyl sulfate, potassium cocoyl sulfate,potassium lauryl sulfate, triethanolamine lauryl sulfate,triethanolamine lauryl sulfate, monethanolamine cocoyl sulfate,monoethanolamine lauryl sulfate, sodium tridecyl benzene sulfonate,sodium dodecyl benzene sulfonate and combinations thereof.

Another preferred class of anionics are salts of N-acyl derivatives ofamino acids.

Preferred emulsifiers are acylglutamate, acylaspartate, acylglycinateand acylalaninate surfactants. Preferably, these are potassium and/orsodium salts of acylglutamate or acyl aspartate or acylglycinate oracylalaninate, wherein greater than 65% of the acyl chains has chainlength C₁₄ or less, e.g., C₈ to C₁₄ (e.g., derived from coconut fattyacid). The acyl chains preferably have greater than 75%, more preferablygreater than 80% C₁₄ or less chain length. Preferably, greater than 75%,most preferably greater than 80% of the chain length are C₁₂, C₁₄ ormixtures thereof.

There are two formats of amino acid surfactants commercially available.One is powder or flake format, which is typically more expensive andhigh in purity. Examples of solid dicarboxylic amino acid surfactantsinclude:

-   -   sodium N-cocoyl-L-glutamate (e.g., Amisoft® CS-11 by Ajinomoto)    -   sodium N-lauroyl-L-glutamate (e.g., Amisoft® LS-11 by Ajinomoto)    -   sodium N-myristoyl-L-glutamate (Amisoft® MS-11 by Ajinomoto)    -   potassium N-cocoacyl_I-Glutamate (e.g., Amisoft® CK-11 by        Ajinomoto)    -   potassium N-myristoyl-L-glutamate (Amisoft® MK-11 by Ajinomoto)    -   potassium N-lauroyl-L-glutamate (Amisoft® LK-11 by Ajinomoto)    -   sodium lauroyl aspartate (AminoFoamer™ FLMS-P1 by Asahi Kasei        Chemical

Corporation)

-   -   sodium lauroyl glutamate (Aminosurfact™ ALMS-P1/S1 by Asahi        Kasei Chemical

Corporation)

-   -   sodium myristoyl glutamate (Aminosurfact™ AMMS-P1/S1 by Asahi        Kasei Chemical Corporation)

Examples of solid monocarboxylic amino acid surfactants include:

-   -   sodium cocoyl glycinate (e.g., Amilite® GCS-11 by Ajinomoto)    -   potassium cocoyl glycinate (e.g., Amisoft® GCK-11 by Ajinomoto)

Liquid amino acid surfactants typically contain 20 to 35% surfactantactive, high in pH and inorganic salt (e.g. 3 to 6% NaCl). Examplesinclude:

-   -   AMISOFT® ECS-22SB: Disodium Cocoyl Glutamate (30% Aqueous        Solution)    -   AMISOFT® CS-22: Disodium Cocoyl Glutamate sodium Cocoyl        Glutamate (25% Aqueous Solution)    -   AMISOFT® CK-22: Potassium Cocoyl Glutamate (30% Aqueous        Solution)    -   AMISOFT® LT-12: TEA-Lauroyl Glutamate (30% Aqueous Solution)    -   AMISOFT® CT-12 TEA-Cocoyl Glutamate (30% Aqueous Solution)    -   AMILITE® ACT-12: TEA-Cocoyl Alaninate (30% Aqueous Solution)    -   AMILITE® ACS-12: Sodium Cocoyl Alaninate (30% Aqueous Solution)    -   AMILITE® GCK-12/GCK-12K: Potassium Cocoyl Glycinate (30% Aqueous        Solution    -   Aminosurfact™ ACDS-L: Sodium Cocoyl Glutamate (25% Aqueous        Solution)    -   Aminosurfact™ ACDP-L: Potassium Cocoyl Glutamate (22%)+Sodium        Cocoyl Glutamate (7%)    -   Aminosurfact™ ACMT-L: TEA-Cocoyl Glutamate (30% Aqueous        Solution)    -   AminoFoamer™ FLDS-L: Sodium Lauroyl Aspartate (25% Aqueous        Solution)

Amphoteric surfactants preferably include derivatives of aliphaticsecondary and tertiary amines, in which the aliphatic radical can bestraight or branched chain and wherein one of the aliphatic substituentscontains from about 8 to about 18 carbon atoms and one contains ananionic group such as carboxy, sulfonate, sulfate, phosphate, orphosphonate. Preferred amphoteric surfactants for use in the presentinvention include cocoamphoacetate, cocoamphodiacetate,lauroamphoacetate, lauroamphodiacetate, and mixtures thereof. Preferredzwitterionic surfactants are derivatives of aliphatic quaternaryammonium, phosphonium, and sulfonium compounds, in which the aliphaticradicals can be straight or branched chain, and wherein one of thealiphatic substituents contains from 8 to 18 carbon atoms and onecontains an anionic group such as carboxy, sulfonate, sulfate, phosphateor phosphonate. Zwitterionics such as betaines are preferred.

In addition, in the subject application the external aqueous phasecomprises 55 to 90% by wt. nanoemulsion of water and glycerol whereinratio of glycerol to water is at least 2.5:1, preferably 2.8:1 to 10:1,most preferably 3:1 to 5:1.

For co-pending application, final diluted composition also has 55 to 90%water and glycerol wherein ratio of glycerol to water is at least 2.5:1,preferably 2.8:1 to 10:1, most preferably 3:1 to 5:1. But, as notedabove, the initial ratio of glycerol to water is 1:2 to 2:1 in theconcentrate emulsion.

In compositions comprising the anionic surfactant and the lauric oils ofour invention, applicants have discovered that a minimum floor level ofglycerol is critical to ensure transparency. If the level of glycerol istoo low (e.g., below 2.5:1 glycerol to water), the transparencydisappears.

Due to high level of glycerol, the level of water activity is within theranges to inhibit bacteria growth, and potentially allows use of onlyfungicide or even no preservatives in nanoemulsions as a final product.

Another factor in maintaining transparency has been found to beprocessing the compositions with at least 1 pass, preferably 2 passes(or more if desired) through a high pressure homogenizer. Thehomogenization pressure is preferably 7000 pounds per square inch (psi)or less (482.6 bar or less), preferably 6000 psi or less (413.6 bar orless), preferably 1500-5000 psi (103.4 to 344.7 bar).

In another aspect, the subject matter of a different application, theinvention relates to an energy efficient process involving only one passthrough the high pressure homogenizer. This process relates toconcentrate emulsions comprising additional fatty acid in the oil phaseand a lower ratio of glycerol to water in the aqueous phase (1:2 to2:1). As described below, the process relates to forming a concentrateemulsion with high amounts of oil (greater than 45% to 80% by wt.composition) and a lower ratio of glycerol to water in the aqueous phase(1:2 to 2:1), intensively mixed by a conventional rotor/stator highshear device at a rotor speed of 3000 to about 7000 rpm, diluting to adesired oil concentration (5 to 40% by wt. of composition) and to adesired glycerol-to-water ratio (at least 2.5:1, preferably 2.8:1 to10:1, most preferably 3:1 to 5), and subsequently subjecting the finalcomposition to only one pass homogenization while still obtaining bettertransparency values than that obtained with one pass through the highpressure homogenizer in the subject invention.

The compositions prepared according to the composition and processes ofour invention have a transparency value of 100 NTU or less, preferably90 NTU or less, more preferably 60 or less. According to the process ofco-pending application, NTU values are at low end (e.g., less than 50,preferably 35 or less), but using only one pass. Such low values arealso achieved using process of the subject application, but two passesare required.

In another aspect, the invention is directed to compositions obtained bya process in which ingredients are directly pumped to a homogenizer for1 or 2 passes at pressure of 7000 psi or less, preferably 6000 psi orless.

Preparation of Nanoemulsion

Subject Application

Nanoemulsions are typically formed in a two stage process.

The first mixing stage is used to form a coarse emulsion. The oil phaseand aqueous phase were heated to from ambient temperature to 60° C.separately such that each phase was clear and uniform; then the oilphase was mixed with the aqueous phase with intensive mixing in aconventional mixer. Intensive mixing can be accomplished viaconventional means including mixing the materials in a stirred tank andpassing the mixture through a rotor/stator mixer such as the Silverson®high shear in-line mixer or mixing them in the vessel with a high shearmixer such as the Scott® Turbon mixer. Alternatively, the coarseemulsion may be created by using a continuous high shear mixing devicesuch as the standard sonolator device produced by Sonic Corporation ofConnecticut. These standard sonolators are normally operated atpressures of 200-500 psi (13.8 to 34.5 bar) to form coarse emulsion.

The second stage of the process is to pass the coarse emulsion through ahigh pressure homogenizer to form the nanoemulsion. Suitable highpressure homogenizers are the Nano DeBee homogenizer of BEEInternational (Massachusetts, USA) and the high pressure sonolatordevice also produced by Sonic Corporation of Connecticut, USA. Thesedevices can be operated up to 1500-5000 psi (103.4 to 344.7 bar) inorder to produce nanoemulsions of less than 100 nm. For lauric oils, forexample either coconut oil or palm kernel oil, only one or two passesthrough the Nano DeBEE or high pressure sonolator is required to reachthe desired nanoemulsion particle size and transparency, with or withoutfatty acid present in the oil phase.

Separate Co-Pending Application

In another aspect, the subject matter of a separate application, aconcentrate emulsion comprising fatty acid or mixture of fatty acidhaving melting point of 30° C. or lower is first prepared. Oil(s) in oilphase are present at greater than 45% by wt., preferably 50 to 85% ofnanoemulsion. The concentrate is also prepared with aqueous phasecomprising glycerol and water, where ratio of glycerol to water is 1:2to 2:1. The concentrate is intensively mixed by a conventionalrotor/stator high shear device at a rotor speed of 3000 to about 7000rpm; the concentrate is then diluted by mixing a solution of water,glycerol or additional surfactant in a separate container and combiningwith the concentrate emulsion to obtain the final emulsion wherein oilis present at level of 40% or below, preferably 5 to 40% and the ratioof glycerol to water is at least 2.5:1, preferably 2.8:1 to 10:1, mostpreferably 3:1 to 5:1. Preferably, the 5 to 40% oil is lauric oil(s). Asnoted up to 30% (0 to 30%) of the 5 to 40% oil(s) may be non-lauric suchthat oil (after dilution) may comprise 3.5% (30% of 5% or 1.5% may benon-lauric) to 40% (assuming 100% lauric oil at start) lauric oil.Finally, the diluted mixture is passed through a high pressurehomogenizer at 6000 psi or less (413.6 bar or less), preferably 1500 toabout 5000 psi (103.4 to 344.7 bar) for one pass. Surprisingly, thesenanoemulsion have a far lower NTU and higher viscosity thannanoemulsions containing fatty acids prepared without going throughconcentrate-dilution process.

In the examples, the following terms are defined as noted below:

Pass #: the number of times the emulsion passes through high pressurehomogenizer

D[4,3]: Volume average diameter or mean diameter or volume average sizedetermined by a Malvern Mastersizer.

Turbidity: Measured by a turbidity meter HACH 2100N at ambienttemperature.

Viscosity: measured by Discovery Hybrid Rheometer at 25° C. and at 4 s⁻¹

EXAMPLES Examples 1-4 and Comparatives A-B

Coarse emulsions were prepared in a one liter ESCO mixer equipped with arotor/stator high shear device (ESCO-LABOR AG, Switzerland). The aqueousphase was added to the ESCO mixer and heated up to 40° C. or untilclear. The oil phase was combined and heated up to 40° C. or till moltenin a separate container. The oil phase was gradually added to theaqueous phase in the ESCO mixer under agitation and/or was intensivelymixed by the rotor/stator device. When the addition of all oil phase wascompleted and the coarse emulsion was formed in the ESCO mixer, thecoarse emulsion was transferred and passed through a high pressurehomogenizer Nano DeBEE 2 times to arrive at the desired turbidity at aprocess pressure of 5000 psi (344.7 bar).

Comp. Example Example Example Example Comp A 1 2 3 4 B Ingredient Wt. %Oil Phase Isopropyl palmitate 10 Carnation ® White Mineral oil 25Coconut oil 35 10 35 10 High Oleic sunflower oil 35 BHT 0.1 Fragrance1.1 1.1 1.1 Aqueous phase Glycerol 47 47 65.4 47.2 65.4 45.5 waterQ.S**. Q.S**. Q.S**. Q.S** Q.S**. Q.S**. Sodium lauryl ether sulfate 6.56.5 9.0 SLES.1EO (70%) (4.5)* (4.5)* (6.3)* Cocoamidopropyl betaine 5.45.4 7.5 5.2 7.5 5.2 (28%) (1.5)* (1.5)* (2.1)* (1.5)* (2.1)* (1.5)*Potassium Cocoyl Glutamate 4.55 6.31 4.39 KOH 0.4 0.5 0.5 Number ofpasses 2 At 5000 psi D_([4,3]) nm 62 — — 65 — — pH 5.3 5.7 5.6 6.3 6.217.23 Turbidity, NTU 163 32.8 22.5 17.5 19.7 199 *number in parentheticalis present as active **quantum sufficit (as much as is sufficient)

The surfactant systems in Examples 1-4 and Comparatives A-B consist ofanionic surfactant (potassium cocoyl glutamate or sodium lauryl ethersulfate) and amphoteric surfactant (cocoamidopropyl betaine) at a ratioof 3 to 1. Comparatives A and B relative to Examples 1-4 demonstratethat excellent transparency (Measured by a turbidity meter HACH 2100N)of less than 40 NTU was achieved by lauric oil, specifically coconutoil, but not by other non-lauric oils.

Examples 5-8 and Comparatives C-E

Examples 5-8 and Comparatives C-E were prepared similarly to Examples1-4 and Comparatives A-B.

Comp C Ex. 5 Ex. 6 Comp D Comp E Ex. 7 Ex. 8 Ingredient Wt. % Oil PhaseUltimate ® 76 35 Coconut oil BHT 0.1 Lauric acid 0.9 0.9 0.9 Prisorine ™3505 2.0 2.0 2.0 Isostearic Acid Fragrance 2.2 Aqueous phase Glycerol44.6 44.6 44.6 32 42.6 42.6 42.6 Water Q.S Q.S Q.S. Q.S. Q.S. Q.S. Q.S.Eversoft ULS-30S 10.5 (2.6)* 10.1 (2.5) (Sodium lauroyl glutamate 25%)Cocoamidopropyl 6.9 (2.6) 6.6 (2.5) betaine (38%) Sodium Hydroxide 0.11Number of passes 0 1 2 2 0 1 2 At 5000 psi D_([4,3]) 1468 93 — 70 556 7775 pH 7.37 7.37 7.17 7.78 6.93 6.88 — Turbidity, NTU 378 50.4 13.2 9392352 88 17.8 Viscosity (at 4 s⁻¹, — 0.98 3.00 0.16 2.77 1.12 18.99 25°C.), Pa · s *Number in parenthetical is percent as active ingredient.

The surfactant systems in Examples 5-8 and Comparatives C-E compriseanionic surfactant (sodium lauroyl glutamate) and amphorteric surfactant(cocoamidopropyl betaine) at a ratio of 1 to 1.

Comparative C relative to Examples 5 and 6 demonstrates that, to achieveoptimum turbidity below 100 NTU, preferably below 60, the compositionshould be passed through homogenizer at pressure of 5000 psi or less forat least 1 pass (Example 5), preferably 2 passes (Example 6). InComparative D, water is present at about 25.5% by wt.(100−(35+0.1+2.2+32+2.6+2.6)), and ratio of glycerol to water is about1.25 to 1. By contrast, in Examples 5 and 6, water is about 12.9%(100−(35+0.1+2.2+44.6+2.6+2.6)) and ratio of glycerol to water is wellabove 2.5:1 (about 3.46:1 in examples). It is seen that glycerol/waterratio is a further criticality.

In Examples 7, 8 and Comparative E, 0.9% lauric acids is added to thecomposition as well as 2.0% isostearic acid. The fatty acid mixture(lauric/isostearic=3/7) has a melting point below 20° C. Adding fattyacids does not provide any advantages while yielding worse transparencymeasured by value if comparing Comparatives C vs. E and Examples 5 vs 7.Surprisingly, after two passes through the homogenizer, the transparentnanoemulsion with fatty acids present in Example 8 results in aviscosity 6 times as large as that of Example 6 (without fatty acidspresent). Transparent gel like consistency is another attribute desiredby consumers.

Examples 9-11 and Comparatives F-G

Examples 9-10 and Comparatives F-G were prepared similarly to Examples1-4 and Comparatives A-B.

Comp F Comp G Example 9 Example 10 Example 11 Ingredient Wt. % Oil PhaseUltimate ® 76 Coconut oil 35 Hydrogenated Palm 35 Kernel Oil Lauric acid2.9 2.9 1.45 0 0 Prisorine ™ 3505 0 0 1.45 2.9 2.9 Isostearic Acid BHT0.1 Aqueous phase Glycerol 43.5 water q.s Galsoft KCGL 14.0 (4.2)(Potassium Cocoyl Glutamate, 30%) TEGO BETAIN C 60 3.0 (1.4)(Cocamidopropyl Betaine, 47%) Number of passes 1 2 1 1 1 At 5000 psi pH6.95 7.11 7.16 7.37 7.17 (at 25° C.), NTU Solidified 55.2 49.6 65.2 Nottransparent (When at 40° C., fluid and transparent) *Number inparenthetical is percent as active ingredient.

The surfactant systems in Examples 9-11 and Comparatives F-G consist ofanionic surfactant (sodium lauroyl glutamate) and amphorteric surfactant(cocoamidopropyl betaine) at a ratio of 3 to 1.

Fatty acid, such as lauric acid, having melting point greater than 40°C. (see Comparative Examples F & G), resulted in non-transparentnanoemulsions at ambient temperature. Fatty acid, e.g. isostearic acidand fatty acid mixture (lauric/isostearic) having melting point below25° C. (Examples 9 and 10), resulted in transparent nanoemulsions atambient temperature.

Surprisingly, Hydrogenated palm kernel oil, having a melting point about40° C. (Example 11), yielded a transparent fluid composition. This issurprising because, even when oil has melting point this high, fluidtransparent nanoemulsion was still formed.

Example 12

The composition as shown in Example 12c of a transparent nanoemulsion isthe same as that of Example 7, but was prepared with the method ofconcentrate emulsion-dilution.

Step 1: Preparation of Concentrate Emulsion:

Emulsions were prepared in a one liter ESCO mixer equipped with arotor/stator high shear device (ESCO-LABOR AG, Switzerland). The aqueousphase, including liquid surfactant, glycerol, and water were added tothe ESCO mixer; mixed to uniformity; and heated up to about 30° C. toabout 40° C. The oil phase was combined and heated up to about 40° C. oruntil melted in a separate container, was gradually added to the aqueousphase in the ESCO mixer under agitation with a scraper. When theaddition of all oil phase was completed, the mixture in the ESCO mixerwas intensively mixed by the rotor/stator device at 3000 RPM to 7000 RPM(rotor speed) for up to 5 minutes. The oil droplet size was measured bya Malvern Mastersizer.

Ex 12a Ingredient Wt. % Oil Phase Ultimate ® 76 Coconut oil 56 BHT 0.2Lauric acid 1.4 Prisorine ™ 3505 Isostearic Acid 3.3 Fragrance 3.5Aqueous phase Glycerol 15.6 Water Q.S. Eversoft ULS-30S (Sodium 11.0(2.8)* lauroyl glutamate, 25%) Cocoamidopropyl betaine (38%) 9.0 (3.4)*D_([4,3],) nm 144 *Number in parenthetical is percent as activeingredient.

In this step, the oil phase consists of 56% coconut oil, far more than35% coconut oil in Example 7. Fatty acids and Fragrance areproportionately more as well. In the aqueous phase, the glycerol/waterratio is about 1.1.

Step 2. The Concentrate Emulsion was Diluted for Further Processing

The diluent as shown in Example 12b was premade by mixing allingredients in a separate container with overhead stirrer, then wascombined in a one liter ESCO with the concentrate emulsion shown inExample 12a at a ratio of 37.5/62.5, arriving a composition as shown inExample 12c, which is the same composition as that of example 7, with anoil level of 35%. The mixture was mixed to uniform with the scraper at40 to about 70 revolution per minute (RPM) while maintaining atemperature of 30 to 40° C.

Example 12b Ingredient Wt. % Glycerol 87.4 Water Q.S Eversoft ULS-30S8.4 (2.1)* (Sodium lauroyl glutamate 25%) Cocoamidopropyl 2.6 (1.0)*betaine (38%) NaOH 0.3 *Number in parenthetical is percent as activeingredient.

Step 3. Homogenization

The diluted emulsion as shown in Example 12c was passed through a highpressure homogenizer Nano DeBEE at 5000 psi (344.7 bar) once, yielding ananoemulsion with a of 24.3 NTU vs.88 NTU in Example 7 and viscosity of2.1 Pa·s vs 1.1 in Example 7.

Example 12c Ingredient Wt. % Oil Phase Ultimate ® 76 Coconut oil 35 BHT0.1 Lauric acid 0.9 Prisorine ™ 3505 Isostearic Acid 2.0 Fragrance 2.2Aqueous phase Glycerol 42.6 Water Q.S. Eversoft ULS-30S (Sodium 10.1(2.5)* lauroyl glutamate 25%) Cocoamidopropyl betaine (38%) 6.6 (2.5)*Sodium Hydroxide 0.11 Number of passes 1 At 5000 psi D_([4,3]) nm 69 pH6.7 , NTU 24.3 Viscosity (at 4 s⁻¹, 25° C.), Pa · s 2.1 *Number inparenthetical is percent as active ingredient.

Example 13

Example 13 was prepared similarly to Example 12, except that palm kerneloil was used.

Step 1. Preparation of Concentrate Emulsion

Example 13a was prepared similarly to Example 12, except that palmkernel oil was used.

Example 13a Ingredient Wt. % Oil Phase Palm Kernel Oil 56 BHT 0.2 Lauricacid 1.4 Prisorine ™ 3505 isostearic Acid 3.3 Fragrance 3.5 Aqueousphase Glycerol 15.6 Water Q.S. Eversoft ULS-30S (Sodium 11.0 (2.8)*lauroyl glutamate, 25%) Cocoamidopropyl betaine (38%) 9.0 (3.4)*D_([4,3]) nm 158 *Number in parenthetical is percent as activeingredient.

Step 2. The Concentrate Emulsion was Diluted for Further Processing.

Diluent shown in Example 13b was combined in a one liter ESCO with theconcentrate emulsion shown in Example 13a at a ratio of 37.5/62.5,arriving a composition as shown in Example 13c.

Example 13b Ingredient Wt. % Glycerol 87.4 Water Q.S Eversoft ULS-30S8.4 (2.1)* (Sodium lauroyl glutamate 25%) Cocoamidopropyl 2.6 (1.0)*betaine (38%) NaOH 0.3 *Number in parenthetical is percent as activeingredient.

Step 3. Homogenization

The diluted emulsion as shown in Example 13c was passed through a highpressure homogenizer Nano DeBEE at 5000 psi (344.7 bar) once, yielding ananoemulsion with a of 31 NTU and viscosity of 2.1 Pa·s, similar to thatof Example 12c.

Example 13c Ingredient Wt. % Oil Phase Ultimate ® 76 Coconut oil 35 BHT0.1 Lauric acid 0.9 Prisorine ™ 3505 Isostearic Acid 2.0 Fragrance 2.2Aqueous phase Glycerol 42.6 Water Q.S. Eversoft ULS-30S (Sodium 10.1(2.5)* lauroyl glutamate 25%) Cocoamidopropyl betaine (38%) 6.6 (2.5)*Sodium Hydroxide 0.11 Number of passes 1 At 5000 psi D_([4,3]) nm 71 pH6.7 , NTU 31 Viscosity (at 4 s⁻¹, 25° C.), Pa · s 2.1 *Number inparenthetical is percent as active ingredient.

1. An oil-in-water nanoemulsion comprising: 1) an internal oil phasecomprising 3.5 to 40% by wt. nanoemulsion composition of a lauric oil,wherein said lauric oil is an oil or oils where saturated C₁₂ lengthfatty acid (12:0) comprises 30% to 85% of the fatty acid compositions ofthe oil or oils; wherein there is a minimum 5% total of lauric andnon-lauric triglyceride oil and 2) an external aqueous phase comprising:i. 55 to 90% by wt. nanoemulsion of water and glycerol, wherein theratio of said glycerol to said water is 2.5:1 and higher; and ii. 3 to12% of a surfactant system comprising water soluble surfactants selectedfrom the group consisting of anionic surfactants, amphoteric surfactantsand mixtures thereof, wherein said anionic surfactant comprises 15% ormore, of the total surfactant system; wherein said composition has aturbidity of less than 100 NTU, wherein said nanoemulsion is prepared bymixing ingredients forming said nanoemulsion and passing through ahomogenizer with 1 pass or more at pressure of 7000 psi or less (482.6bar or less).
 2. The nanoemulsion according to claim 1, wherein oildroplets formed in nanoemulsion have an average particle size, D[4,3],of 100 nm or lower.
 3. The nanoemulsion according to claim 1, whereinthe anionic surfactant is selected from the group consisting of alkylsulfates, alkyl ether sulfates, N-acyl derivatives of amino acid andmixtures thereof.
 4. The nanoemulsion according to claim 1, whereininternal oil phase additionally comprises 0.1 to 7% by wt. ofnanoemulsion of a fatty acid or mixture of fatty acids and wherein saidfatty acid or mixture has a melting temperature of −10° C. to 30° C. 5.The nanoemulsion according to claim 1, wherein said lauric oil isselected from the group consisting of coconut oil, palm kernel oil,babassu oil, tukum oil, murumuru oil, ouricuri oil, cohune oil, cupheaoil, lauric algal oil and mixtures thereof.
 6. The nanoemulsionaccording to claim 1, wherein lauric oils comprise 30% to 85% lauricacid ester linked to glycerol moiety.
 7. A composition according toclaim 1, wherein non-lauric triglyceride oils high in unsaturation withiodine value of above 50 partially replaces lauric oil at a level of 0to 30% of lauric oil, but wherein there is a minimum level of 3.5%lauric oil.
 8. The composition according to claim 7, wherein saidnon-lauric high IV oils are selected from the group consisting ofsunflower oil, grapeseed oil, argan oil and mixtures thereof.
 9. Thenanoemulsion according to claim 1, wherein the ratio of said glycerol tosaid water is 2.8:1 to 10:1 or 3.0:1 to 5:1.
 10. The nanoemulsionaccording to claim 9, wherein the ratio of said glycerol to said wateris 3.0:1 to 5:1.
 11. The nanoemulsion according to claim 1, wherein theanionic surfactant comprises 40% to 85% of the total surfactant system.12. The nanoemulsion according to claim 11, wherein the anionicsurfactant comprises 50% to 85% of the total surfactant system.
 13. Thenanoemulsion according to claim 1, wherein said composition has aturbidity of less than 80 NTU.
 14. The nanoemulsion according to claim13, wherein the turbidity is 60 to
 1. 15. The nanoemulsion according toclaim 2, wherein the average particle size, D[4,3] is 20 to
 95. 16. Thenanoemulsion according to claim 4, wherein the melting temperature is 0°C. to 25° C.
 17. The nanomeulsion according to claim 6, wherein lauricoils comprise 40% to 55% lauric acid ester linked to glycerol moiety.